Read Multiple Input Files in c++ and c# with Command Line Arguments 69
Shows how to read from multiple input files with and without using command line arguments in c plus plus and c sharp programs.
c++ code:
#include ＜iostream＞ //for cout
#include ＜fstream＞ // for ofstream/ifstream
#include ＜string＞ //for ＜＜ and getline
//int main()
int main(int argc, char *argv[])
{
if (argc ＜ 3)
{
std::cerr ＜＜ "provide 2 input file names for command line args in properties."
＜＜ std::endl;
std::cin.get();
return -1;
}
std::cout ＜＜ "There are " ＜＜ argc ＜＜ " arguments." ＜＜ std::endl;
for (int i = 0; i != argc; ++i)
{
std::cout ＜＜ argv[i] ＜＜ std::endl;
}
//std::ifstream input_file1("test1.txt");
//std::ifstream input_file2("test2.txt");
std::ifstream input_file1(argv[1]);
std::ifstream input_file2(argv[2]);
std::ofstream output_file("test.txt.out");
std::string line;
int line_no = 1;
for (; std::getline(input_file1, line); ++line_no)
{
std::cout ＜＜ line_no ＜＜ ":" ＜＜ line ＜＜ std::endl;
output_file ＜＜ line_no ＜＜ ":" ＜＜ line ＜＜ std::endl;
}
for (; std::getline(input_file2, line); ++line_no)
{
std::cout ＜＜ line_no ＜＜ ":" ＜＜ line ＜＜ std::endl;
output_file ＜＜ line_no ＜＜ ":" ＜＜ line ＜＜ std::endl;
}
//if (input_file1)
if (input_file1 && input_file2)
{
input_file1.close();
input_file2.close();
output_file.close();
}
std::cin.get();
return 0;
}
c# code:
using System;
using System.IO;//to use StreamReader
namespace lec1csharp
{
class Program
{
//static void Main()
static void Main(string[] args)
{
if (args.Length ＜ 2)
{
Console.Error.WriteLine(
"provide 2 input file names for command line args in properties.");
Console.ReadLine();
return;
}
Console.WriteLine("There are {0} arguments.", args.Length);
for (int i = 0; i != args.Length; ++i)
{
Console.WriteLine(args[i]);
}
//StreamReader input_file1 = new StreamReader("test1.txt");
//StreamReader input_file2 = new StreamReader("test2.txt");
StreamReader input_file1 = new StreamReader(args[0]);
StreamReader input_file2 = new StreamReader(args[1]);
StreamWriter output_file = new StreamWriter("test.txt.out");
string line = "";
int line_no = 1;
for (; (line = input_file1.ReadLine()) != null; ++line_no)
{
Console.WriteLine(" {0} :{1}", line_no, line);
output_file.WriteLine(" {0} :{1}", line_no, line);
}
for (; (line = input_file2.ReadLine()) != null; ++line_no)
{
Console.WriteLine(" {0} :{1}", line_no, line);
output_file.WriteLine(" {0} :{1}", line_no, line);
}
//if (input_file1 != null)
if (input_file1 != null && input_file2 != null)
{
input_file1.Close();
input_file2.Close();
output_file.Close();
}
Console.ReadLine();
}
}
}
#cplusplus #csharp #tutorial
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